Control units of this type are increasingly replacing typical mechanical external shifters, which rigidly couple a shift/selection lever in the passenger compartment of a motor vehicle to a selector fork of a transmission, for example, via a linkage or a cable pull mechanism.
To allow secure shifting, the path to be covered by the selector fork between two shift positions may not be too small. Correspondingly, the path which the selector fork covers between a neutral position and a synchronization position generally makes up a significant part of the total path to be covered from the neutral position into the shift position. This is correspondingly true for the paths over which the shift/selection lever must be displaced between its neutral position and the shift position or the synchronization position. The time required for the displacement between neutral position and synchronization position therefore makes up a significant component of the total duration of a shift procedure. This total duration may be decreased without loss of shift comfort if the time required for the displacement between neutral position and synchronization position is decreased in relation to the duration of the synchronization procedure itself.
A typical shift-by-wire control unit, as is known, for example, from DE 103 04 588 B3, essentially only requires a user input of arbitrary form to control the changeover to a gear specified by the user input. The shift procedure then runs according to a predefined time program. The duration of the shift procedure is thus essentially fixed. The shorter this duration, the more rapidly the shifter reacts to the user input, but the more noisily and uncomfortably for the passengers the shift procedure runs. The possible desire of the driver for a faster or slower shift procedure may not be taken into consideration.
The object of the invention is to provide a shift-by-wire control unit which allows the performance of a shift procedure in a shorter time, which may be influenced by the driver, however.